Interlocking relay.



No. 885,061. PATENTED APR. 21, 1908.

T. L. LEE. INTERLOGKING RELAY.

APPLICATION FILED JUNE 6, 1907.

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INTERLOCKING RELAY.

APPLICATION FILED JUNE 6, 1907.

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Mtwwm Inventor ent invention. Fig.

THOMAS L. LEE, QF WESTFIELD, NEW JERSEY",

ASSIGNOB, TO THE HALL SIGNAL COMPANY,

A CORPORATION or MAINE.

,INTERLOCKING RELAY.

Specification 0:! Letters Patent.

Patented Apri1 21,- 1908.

Application filed. June 6, 1907. Serial No. 377,552.

To all whom it may concern:

Be it known that I, THOMAS L. LEE, a citizen of the United States, residing at Westfield, in the county of Union and State of New Jersey, have invented a certain new and useful Improvement in Interlocking Relays, of which the following is a specification, reference'being had therein to. the accompanyj ingvldrawings, forming a part thereof.

y invent on relates to relays for use in connection wlth electrical a paratus in which it is necessary to arrange or automatically preventing the contemporaneous o ening or closing of two or more circuits, as, or example, in connection with an electric alarm bell or signaling the a proach of trains on a single-track railroa and the object of the invention is to produce an interlocking relay for this Lpur ose which is simple in COIlSlZIllC-'. -t1on an re iable in operation.

To this end the invention comprises a relay in which two or more armatures controllin circuits are interconnected mechanically y detent mechanism operating, after one armature has been moved, to restrict'the movement of another armature.

The invention comprises further an ar rangement by which the detention of the second armature is continued, after the return of the first armature, until the impulse tending to move the second armature is discontinued.

Other features of the invention will be noted in connection with the description of the illustrated embodiment thereof.

I will now describe the embodiment oi -my invention illustrated in the accompanying drawings, and'will thereafter point out my inventionin claims.

.In the drawings Fi ure 1 is a side elevation of an interlockin re ay embodying the pres- 2 1s a bottom plan view of the relay. Fig. 3 is a detail view, in side elevation, of the detent mechanism; on an enlarged scale. Fig. 4 is a diagrammatic representation of an alarm-bell installation in which the rela is used.

The illustrate rela has two magnets 1 and 2 mounted on a ase plate 3 and pro vided with pole pieces 4 and 5. Armatures 6 and 7 are pivoted on depending lugs 8 on the base plate and cooperate respectively with the pole pieces 4 and 5. The armatures carry flat metal contact fingers 9 and 10 fixed to the armatures but insulated from them by insulating blocks 11. The contact fingers are connected, by flexible conductors 12, with binding posts 13 .on the base plate.

.Each contact finger carries a contact spring I l-cooperating with a stirrup shaped fixed contact 15 mounted on an insulating block 16 and connected with a binding 0st -17. The contact springs 14 and the fixed contacts 15 constitute backcontacts, being engaged and operating to close their circuits when the magnets are denergized and the armatures fall by gravity.

In order that the armatures may operate also, when necessary, to interrupt clrcuits when they fall, each contact finger is 'provided with an upwardly-extendingcontact spring 18' arranged'to engage a fixed contact 19 when the armature is in raised osition. The front contacts 19 are mounte on the insulating block 16 and connected with bindin posts 20. a l e detent mechanism by whlch the armatures are rendered interlocking is shown particularly in Fi 3. The armatures are provided with 100 ing arms 21 and 22 arranged to cooperate with two detents pivotally mounted on ashaft 23 carried in a yoke 24 mounted onthe base plate. I The detent 25 has an upwardly-projecting arm 26 arranged to'en age, when in operative position, the shouldered extremity 27 of the lockin arm 22. A counterbalance 28 on the etent tends to swing the locking arm 26 to the left so as to keep it normally in inoperative position, clear of the end of the locking arm 22. A roller 29 is journa'led in a bracket 30 on the locking arm 21, and engages an inclined cam surface 3 1 on the detent 25. When the armature 6 is released and falls the roller 29 operates to swing the detent 25 to the right, as shown in Fig. 3, and the arm 26 assumes a position beneath the end of the locking arm 22. If now the armature 7 be released by-the magnet 2 it is'prevented from falling,v and the circuits controlled by the contact finger 10 are not affected. As long as the locking arm 22 rests on the detent arm the detent is prevented from returning to inoperative position,

even after the armature 6 and the locking arm 21 have been raised again to normal 0- sition, and thus the detent is not restored to inoperative position by the counterbalance 28 until both armatures are restored to normal position.

The detent 32 is similar in form and operatures are he to flow through the ma net 1.

tion to the detent 25, but serves to lock the locking arm 21 when actuated by the locking arm 22, so that the armatures are mutually interlocking.

Fig. 4 shows the electrical connections for an alarm bell on a single-track railroad. The rails 33 are divided and insulated at a point 34 opposite the station, and are connected at either side of this point with the terminals of batteries 35 and 36. The rails are also connected with theterminals of the magnets 1 and 2, so that normally a constant current flows throu h each magnet and the armald in raised position. The front contacts of the relay are not used in this application of the device, but the binding posts 13' and 17. are connected in circuit with a battery 37 and an alarm bell 39, so that upon the closing of either back contact of the relay the bell Wlll ring.

Supposing that a train a proaches from the left,"a's soon as it enters t e left-hand insulated section of the track the wheels" of the train short-circuit the battery 35 in the usual manner and the current substantially ceases The armature .6 then drops and the contact finger 9 closes the bell circuit and the bell rings. The detent mechanism then occupies the position of Fig. 3. As soon as the forward wheels of the train reach the right-hand portion of the track the battery 36 isshort-circuited and the armature'7 is released. This armature is prevented from falling, except for the short distance necessary to bring the locking arm 22 into contact with the detent arm 26, and the right-hand branch of the bell circuit is not closed. As soon as the train leaves the left-hand portion of the track the armature 4 is raised, opening the bell 'circuit through the contact finger 9, and as the armature7 is still locked b the detent 25 the bell ceases to ring. hen the train passes off from the right-hand section of the track the armature 7 is raised to normal position and the detent 25, being thus released from contact with the locking arm 22, returns to normal position:

When a train approaches from the right a similar series of operations occurs, with the parts of the relay operating in reversed reation. v

The above-described operation of the system is such as to cause the bell to ring, upon the approach of a train in either direction,

until the train passes the station, and then to cease rin ing, whereas with an ordinary relay the bel would continue to ring until the train passed from the second insulated section of the track.

The application of the relay above described is only one of many which will occur to those skilled in the art, and it is apparent, furthermore, that various modifications may be made in the embodiment of my invention shown and herein described within the nature and scope of theinvention.

I claim:

1. An interlocking relay having, in combination, two magnets, two armatures controlled thereby and operating to control electric circuits, and two movably-mounted detents "each of which is arranged to be thrown into operative position by movement of one armature and to operate, when in such position, to restrict the movement of the other armature.

2. An interlocking relay having, in combination, two magnets, two armatures controlledthereby and o crating to control electric circuits, a pivota ly-mounted detent provided with an upwardly-extending arm and an inclined cam surface thereon, a rollcarried by one armature and engaging the cam surface so as to swing the detent arm laterally into operative position when said armature is moved in one direction, and means carried by the other armature and arranged to engage the upper end of the detent arm in such operative position to restrict the downward movement of said means.

3. An interlocking relay having, in combination, two magnets, two armatures controlled thereby, contact fingers mounted on but insulated from the armatures, fixed contacts cooperating with the fingers, a locking arm mounted on each armature, and two detents each of which is arranged to be engaged and actuated by one locking arm and to engage and lock the other locking arm to prevent contemporaneous operation of the armatures and their contact fingers.

In testimony whereof I have aflixed my signature in presence of two witnesses.

THOMAS L. LEE.

Witnesses:

BERNARD CowEN, C. C. DAVISON. 

